FR2530007A1 - RADIAL SUPPORT FOR TUBULAR HEAT EXCHANGER PLATE - Google Patents

Abstract

RADIAL SUPPORT FOR TUBULAR HEAT EXCHANGER PLATE. A HEAT EXCHANGER INCLUDING A VIROLE 14 INSIDE WHICH IS MOUNTED A ENCLOSURE 12 SURROUNDING THE TUBES, AND THE SUPPORT PLATES 16 OF TUBES MOUNTED TRANSVERSALLY THEREIN, IS EQUIPPED WITH RADIAL SUPPORT MEANS. THESE MEANS INCLUDE A THREADED CYLINDRICAL ELEMENT 40 FORMING A CYLINDER AND SCREWED IN THE ENCLOSURE 12 IN ORDER TO POSITION THIS IN RELATION TO THE FERRULE 14. A LOCKING SCREW 46, SCREWED INTO THE CYLINDRICAL ELEMENT 40 FORMING A CYLINDER, EXTENDS TOWARDS L 'INTERIOR SO AS TO BUG AGAINST A TUBE SUPPORT PLATE 16, WHICH ALLOWS POSITION ADJUSTMENT OF THIS TUBE SUPPORT PLATE 16 IN RELATION TO THE ENCLOSURE 12. APPLICATIONS IN PARTICULAR TO STEAM GENERATORS OF NUCLEAR POWER PLANTS.

Description

Radial support for tube heat exchanger plate.

  The present invention relates generally to heat exchangers which utilize a plurality of tubes placed therein, and more particularly relates to mechanisms which provide radial support to the tubular plate and radially transmit the forces of the tubular plate. The present invention relates more specifically to a support mechanism

  which transmits the radial forces to the outer shell of a genera-

  steam generator which comprises two ferrules mounted coaxially.

  In nuclear generator systems, it is generally

  heat exchangers to transmit the heat of a

  dioactive to a non-radioactive fluid which will then pass into a turbine.

  These two fluids are isolated from one another to prevent contamination

  A heat exchanger of this type, when

  water as a means of transmitting heat, is called "genera-

  steam generator and this name will be used in the present description.

  Typically, a steam generator of this kind has an outer shell that contains both the radioactive fluid and the non-fluid.

  radioactive material, each of which flows in individual passages

  tincts Inside this outer shell, the steam generator is compartmentalized so as to allow a heat exchange between the fluids without these can come into physical contact with each other To perform this operation, we make pass one of the fluids in several tubes

  thermally conductive while the other fluid flows around and around

  tact of the outer faces of these tubes.

  The above-mentioned heat exchanger tubes may be U-shaped so as to provide fluid communication between two adjacent compartments at the same end of the heat exchanger or, alternatively, the tubes may be straight and to port

  compartments at opposite ends of the heat exchanger.

  In either case, the fluid flowing around the outside faces

  heat exchanger tubes, may cause lateral movement

  and possibly significant vibrations in the tubes.

  side support to the heat exchanger tubes, which may have

  a significant length, we have the tube support plates in the in-

  Inside the steam generator These tube support plates are generally

  The flat heat exchanger tubes are introduced into these holes with a minimum of clearance, so that the lateral displacement of the tubes is limited by the tube support plate. understand that the tube support plate is typically designed not to prevent longitudinal movement of the tubes in the plate but only to provide a support which prevents radially lateral displacement to the tubes, which would otherwise occur because of the fast passage

  fluid around their outer cylindrical faces.

  In steam generators which use a double ferrule construction, the tube support plates being mounted inside the inner ferrule, it sometimes becomes necessary to radially support the tube support plates so as to radially transmit them. effor

  to the outer shell because of the greater resistance of the latter.

  Even in circumstances that do not require this transmission of ef-

  strong radial to the outer shell, it is generally necessary to strengthen the inner virc in a certain way so that it can support the radial effoy exerted by the tube support plate In the latter case, the inner virc should be strengthened locally in the region where can E

  the forces transmitted by the tube support plate.

  The main object of the present invention is therefore to provide a simple mounting for supporting the tube support plates in a manner that allows easy adjustment without exerting excessive force on the ferrule

  inside the steam generator.

  In order to achieve this object, the present invention consists of a heat exchanger comprising a generally cylindrical shell, a generally cylindrical shell mounted concentrically inside the shell.

  this shell, a bundle of heat exchanger tubes arranged in

  envelope, several tube support plates placed inside the

  of the envelope transversely to the tubes to provide them for lateral support, and a means for adjusting the position of these plaquessupports

  relative to the casing The characteristic of the present invention resides

  in that cylindrical elements forming cylinders are mounted on the envelope so as to extend axially from the latter

  in planes that coincide with the support plates.

  Cylinders have an external thread engaged in an opening ta-

  of the envelope so as to allow the positioning of the envelope

  With respect to the ferrule, the cylinder elements also have a tapped central bore which receives a locking screw which abuts against the support plate in order to allow the adjustment of the position thereof to

-2530007

inside the envelope.

  The present invention provides a means for radially supporting

  a tube support plate in a steam generator while transmitting

  both the radial forces of the tube support plate directly to the

  to avoid possibly damaging the envelope of least resistance during periods of intense radial

tube support plate.

  The present invention will be well understood on reading the

  following description made in connection with the attached drawings, in the-

which: -

  Figure 1 illustrates a steam generator;

  FIG. 2 illustrates a device according to the prior art,

  providing a radial support to a tube support plate;

  FIG. 3 represents a part of the mechanism of the plate

  tube support of Figure 2; Figure 4 illustrates the radial tube support device according to the present invention; and FIG. 5 is a detailed view of the transmission structure

  efforts according to the present invention.

  FIG. 1 shows a steam generator 10 which is internally divided into distinct compartments. It comprises an inner shell 12 and an outer shell 14.

  all parts of its heat exchanger equipment

  12 is an axial support for the tube support plates 16 and is also a partition which promotes the flow of fluid into the steam generator.

  which passes a fluid from an inlet manifold (indicated by the

  arrow I) to an outlet manifold (indicated by the arrow 0).

  tinct flows in the steam generator around the cylindrical faces ex-

  This fluid communicates thermally with the fluid that circulates in the tubes 18 and is heated by contact with the outer faces of the tubes 18. The heated fluid flows in the vicinity of the tubes and it heats up as and when it travels the path indicated by the arrows H When it leaves the steam generator, the fluid is in the form of steam and it is sent to the turbine of a generating system

  of electric current to then return to reduced temperature in general.

  This cooled fluid passes between the inner ferrule 12 and

  external shell 14 of the steam generator (as indicated by the arrows

  C) and it is brought back to the region next to the tubes 18 to be heated again This fluid is therefore both in the state

  liquid L and in the gaseous state G inside the steam generator.

  In Figure 1 and in the illustration described above, the fluid passing through the tubes 18 and indicated by the arrows I and O, is radioactive because it flows directly from a nuclear reactor to the steam generator. Likewise, it should be clearly seen that the other fluid circulating inside the steam generator, around the outer face of the tubes 18 and indicated

  by the arrows C and H, is not radioactive and one of the functions of the gen-

  The steam generator 10 is to transmit the heat of the radioactive fluid to the non-radioactive fluid while keeping them separated from each other. It should also be understood that in steam generators of different design, it would be possible to pass the non-radioactive water in the tubes 18 and radioactive water around these tubes 18, as an alternative to the method

  described above However, it must also be understood that the present

  tion applies to one or the other type of steam generator and,

  steam generators that use straight tubes instead of

  U-shaped tubes shown in Figure 1.

  The support plate 16 of tubes of a steam generator is supported

  characterized, in the axial direction, by a plurality of wedges 19 welded to the inner ferrule 12. A radial support of the tube support plate must also be provided by certain means (not shown in FIG.

figure 1).

  FIG. 2 illustrates a means of providing the radial support required

  This device, well known to those skilled in the art, uses a plate of special shape which is introduced into a hole formed radially in the inner shell 12. a weld 21 on the inner ferrule 12 so as to form with it a rigid assembly The plate 20 is pierced with one or more

  radial holes which are tapped and in which

  The plate 20 is radially aligned with the tube support plate 16 so that the threaded members 22 can be extended.

  from the plate 20 to the tube support plate 16 An intermediate block

  24 is then placed between the threaded elements 22 and the plate

  support 16 tubes, in the immediate vicinity of the latter Keys 26 are then driven between the intermediate block 24 and the support plate 16 of tubes to ensure physical contact between them The keys 26 are then welded to the intermediate block 24 which is welded, in turn, to

  threaded elements 22 which may already have been rigidly attached, by welding.

  This arrangement provides an assembly consisting of plate 20, threaded members 22, intermediate block 24 and keys.

  26, the whole being rigidly connected to the inner ferrule 12.

  Before welding together the elements of this radial support device, it must be ensured of their respective dimensions in order to center the support plate 16 of tubes inside the inner ferrule 12. It must be clear that the use of keys 26 for

  accurately center the support plate 16 of tubes within the gen-

  It is difficult, because these keys are, typically, unsuitable for making fine dimensional adjustments. Other disadvantages of this method are that of the prior art.

  in that, in order to ensure localized reinforcement of the ferrule

  12, the thickness of the plate 20 must be such that this plate de-

  radially on the outside of the inner ferrule 12, on a

  As shown in Figure 2, this overflow can

  impede the laminar flow of the cooled liquid, as indicated by the

  In addition, in nuclear generator systems, it is often

  desirable to minimize the number of individual elements within the

  of the steam generator. From the foregoing description, it is

  Obviously, each radial support device, as shown in Figure 2, consists of many individual elements that can each loosen during operation and cause a potentially harmful situation.

  In addition, it must be clear that the total cost of the process de-

  The cost is derived from the need to drill the virus.

  the inside 12, to form the plate 20 and to accurately position the support plate 16 of tubes inside the inner shell 12 by means of

  repeated adjustments of threaded elements 22 and keyways 26

  It is difficult and costly to manufacture the plate 20 shown in FIG. 3. The plate 20 is shaped to present

  an outer portion 32 which is arcuate in order to adapt to the sur-

  outer circumferential face of the inner ferrule (reference 12 in FIG. 2), while an inner portion 34 is formed to fit into the radially drilled hole in the inner ferrule 12 The inner portion

  34 and the outer portion 32 of this plate must be formed with

  In addition, the two holes 36 must be drilled into the plate 20 and tapped to receive their elements.

  associated threads (reference 22 in Figure 2).

  The present invention is illustrated in FIG.

  the inner ferrule 12 and the outer ferrule 14, and the plate

  support 16 of tubes and a shim 19 which provides axial support to this

  The present invention comprises an element 40 forming a cylinder, or jack screw, which passes through a hole drilled in the inner shell 12 and is located

  in contact with the inner cylindrical face of the outer shell 14.

  When the element 40 forming cylinder is thus mounted, it is fixed rigidly to

  the inner ferrule 12 by means of welds, for example, as shown in FIG.

  As soon as the element 40 forming a cylinder is rigidly attached to the inner shell 12, while being in physical contact with the outer shell 14, all the radial forces supported by the inner ring 12 in the region of FIG. the element 40 forming a cylinder, will be transmitted radially to the outer shell more robust 14 The element 40 forming cylinder is provided with a central bore 44 whose shape is such that it allows to

  The latter ends with a head 47 with a plurality of

  it is easy to see that, in the long run,

  the threaded element 46 from the element 40 forming a cylinder, it is possible to regulate

  accurately the radial position of the head 47 to position radially

  Although, in the preferred embodiment of the present invention, a threaded element 46 is used which is screwed into the element 40 forming a jack, it should be clearly seen that a variant of

  the construction could provide a rod arranged so as to be able to slide

  ser inside the bore 44 of the element 40 forming cylinder.

  As shown in FIG. 4, it will be apparent to those skilled in the art that the head 47 of the threaded member 46 may be radially displaced either inwardly or outwardly by rotating the head 47. This movement can be achieved by means of an open key and it does not require any special tools. It should be further seen that, depending on the pitch of the threads of the threaded element 46, the head 47 can be positioned radially

  and accurately inside the steam generator When the plate-

  tube support 16 exerts a radial force directed outwards, one must

  to see moreover that this effort is transmitted directly to the outer shell.

  14 without significant deformation of the inner ferrule 12 This tran

  The direct mission of the effort eliminates the need for significant reinforcement

  This device also minimizes the total number of elements in the region of the tube support plate 16.

  required to be included in the steam generator.

  By comparing the method according to the prior art, shown in FIG. 2, with the present invention illustrated in FIG. 4, it will be clearly seen that the advantages of the present invention are apparent. The total number of elements that make up the present invention does not include that the element 40 forming cylinder and the threaded screw 46 blocking, while the method according to art

  prior art used a plate 20, threaded elements 22, an intermediate block

  24 and a key 26 Similarly, the manufacturing cost of the device

  according to the present invention is significantly lower than

  It has been explained above that the complex shape of the plate 20, illustrated in FIG. 3, is difficult, and therefore expensive, to manufacture while the element 40 forming a cylinder and blocking screw 46, shown in FIG. 5, are easy to manufacture on

classic machines.

  Figure 5 shows in more detail the element 40 forming

  cylinder and the locking screw 46 The element 40 forming a cylinder comprises a first

  one end 50 which is shaped so as to fit against the inner cylindrical face of the outer shell (reference 14 in FIGS. 1 and 4), while its other end is provided with a means for rotating it in the hole formed in the inner ferrule 12 In FIG. 5, this means is represented by two holes 52 in which a wrench can be introduced to provide a sufficient torque for the rotation of the cylinder element inside a threaded hole. which is pierced radially in the inner ferrule (reference 12 in Figure 4) The outer cylindrical surface of the element 40 forming cylinder can be provided with a threaded portion 48 that can be screwed into the hole mentioned above of the ferrule

  The element 40 forming a cylinder is also provided with a central bore.

  tral 44 which can be tapped in order to receive the locking screw 46 or

  As described above, the locking screw 46 is equipped with a multi-headed head 47 which allows it to be rotated using

a classic open key.

  After having adjusted the locking screw 46 in the element 40 forming a jack in order to correctly position the tube support plate (reference 16 in FIG. 14), this locking screw 46 can be welded to the element 40 forming a jack in order to to rigidly assemble these elements to each other and to ensure that no relative movement between these elements will occur

  after installation This welding attachment is indicated by the reference

49 in Figure 4.

  It should be clear to those skilled in the art that the present invention

  constitutes a device which is relatively easy and inexpensive to manufacture.

  quer but which provides a radial support to a tube support plate, in a way that allows to accurately adjust the position of the support plate

  of tubes inside the steam generator. In addition, the present invention

  This invention provides a means for effectively transmitting to the outer shell of the steam generator the radial forces exerted by the tube support plate, without requiring a significant strengthening of the inner shell of the steam generator in the region of the support plate. tubes From

  It should be understood that the present invention minimizes the

  number of elements that must be included in the steam generator to ensure this radial support and it also reduces the adverse effect on the flow

  of fluid around the radial support device according to the present invention.

tion.

  The present invention is not limited to the exemplary embodiments

  described above, it is, on the contrary, likely to

  laughing and changes that will occur to those skilled in the art.

Claims (4)

R E V E N D I C A T IO N S   1 Heat exchanger comprising a ferrule generally cylindrical   jig (14), a generally cylindrical casing (12) mounted concentrically   inside this ferrule (14), a bundle of heat-exchange tubes arranged inside the casing (12), several plates   tube supports (16) placed inside the transverse casing (12)   to the tubes (18) to provide them with lateral support, and means for adjusting the position of these support plates (16) relative to the casing (12), this heat exchanger being characterized in that that cylindrical elements (40) forming cylinders are mounted on the casing (12) so as to extend axially from the latter in   planes which coincide with the support plates (16), these elements (40) formally   cylinder jack having an external thread (48) engaged in a threaded opening of the casing (12) so as to allow positioning thereof relative to the shell (14), these elements (40) forming cylinders further having a tapped central bore (44) which receives a locking screw (46) abutting the support plate (16) to allow adjustment   the position of this support plate (16) inside the envelope (12).   2 heat exchanger according to claim 1, characterized in that the element (40) forming a cylinder is welded to the casing (12) when this   last is positioned correctly with respect to the ferrule (14).   3 heat exchanger according to one of claims 1 or 2,   characterized in that the cylinder member (40) and the blast member (46)   cage are rigidly fixed to each other, after a position adjustment of the support plate (16) of any tubes   Heat exchanger according to one or more of claims 1, 2 or 3,   characterized in that the locking screw (46) has at its radial end   the innermost one, a multi-headed head (47)   be the support plate (16) of tubes and which is used to rotate   more easily the screw (46) blocking.